US2980029A - Rotary vane type pump - Google Patents

Description

April 18, 1961 L. J. MoULToN ET AL 2,980,029

ROTARY VANE TYPE PUMP 3 Sheets-Sheet 1 Filed 00's. 5, 1956 INVENTORS NR nw/3 L fw N. T7 .0 M0, @W JJM/WH R 4. u, a .J Z

April 18, 1961 L. J. Mo'JLToN ET AL 2,980,029

ROTARY vANE TYPE PUMP Filed Oct. 5, 1956 3 Sheets-Sheet 2 4 rra HUE V April 18, 1961' L, J, MOULTON Ef AL 2,980,029

ROTARY VANE TYPE PUMP 3 Sheets-Sheet 5 Filed Oct. 5, 1956 f//Msx [IL m o INVENTORS J. MouLTo/v BY A. L DSA/@LEE ROTARY VANE TYPE PUMP Fried oct. s, 1956, ser. No. 614,180 f 4 claim. (c1.103 1s6) The invention relates to a rotaryA vane type pump adapted to handle liquids having corrosive properties and/or which may contain foreign material in forms tending to be either destructive to certain of the pump components or to be otherwise detrimental to eflicient pumping. An object of the invention is to providea heavy duty rotary vane type pump suitable, for example, in oil fields e.g. for gathering crude oil of various types land capable of operation without substantial slippage losses.

A further object is to provide atruly balanced and relatively highly efficient rotary vane type pump adapted for operation to pump low viscosity and highly volatile liquids and having effectual and practicable provision for minimizing pressure drop in the liquid supply and'distribution passages leading to t-he pumping chambers.

Another object is to provide a pumping chamber or barrel member for a vane type pump having improved features contributing to efficient pumping and which is capable of being economically manufactured and economically serviced inthe field.

`Other objects of the inventioninclude provision of a rotary vane type pump so constructed that the radial movements of the vanes, apart from their normal action as vanes, will act eiciently as pistons; a balanced rotary vane type pump which is capable of satisfactorily handling raw crude petroleum notwithstanding -practically States Patent unavoidable sand and silt content thereof land which pump has effectual provision for minimizing unbalance in operation in event oneor more of the vanes becomes damaged; a rotary vvane type pump having provision for completely isolating the necessary-rotor supporting shaft bearings from contact with the fluid being pumped; and

a rotary vane type pump wherein inspection and replace- Y' ment of the van elements and other components of the pump which are apt to 'suffer wear or damage are simple operations capable of being performed expeditiously in the field through the use of 'a' very few and commonly available tools.

Other objectsand features of the invention will become apparent from the following description of one preferred form of the present pump `as shown in the accompanying drawings.

In the drawings Fig. l is a small scale sectional plan view of the main housing po-rtion of the present pump, the housing being broken away substantially along the line 1 1 of Figt 2. Fig. 2 is a sectionalv side elevation of the pump assembly broken away as indicated bythe lines 2 2 on Figs. l and 3. Fig, 3 is a central vertical secl tional view through the pump assembly taken along the plane indicated by the lines 3 3 on Fig. 2. Fig. 3a is .an enlarged scale fragmentary view of portions of the construction according to Fig. 3, somewhat modified.

Fig. 4 is a detail cross sectional view showing the transverse shape of one inlet and one outlet passage in the housing near its base portion, taken as indicated by the line 4 4 on Fig. 2. Fig. 5 is a relatively enlarged fragmentary partlyr diagrammatic end view of thepurnpM Patented Apr. 18, 1961 ICC . 2 sleeve or barrel (hereinafter usually sleeve). Fig. 6 is a top plan reduced scale view of the sleeve. Fig. 7 is a relatively enlarged partly sectional detail side view show ing one of the pumping vane assemblies or vane units. Fig. 8 is a further enlarged transverse cross sectional view through the vane unit of Fig. 7, taken along the line 8 8 thereon, Fig. 7 showing one of several loading springs of the vane in a relaxed condition. fFig. 9 is a view corresponding to Fig. 7, partly in section and showing ya modied vane unit construction.

The housing construction or housing means of the present pump mechanism A as shown in Figs. l, 2 and 3, preferably comprises a main body or housing member 1, preferably made as a one-piece hollow metal casting with an integral mounting base portion 2. and a central basically circular drum portion 3, and two rugged and preferably both detachable end closure members 4 and 5, shown as end caps, of mutually similar form operatingly integral with the housing member 1, being shown as secured Vthereto by screws 4' and 5 in positions closing the ends of a generally cylindrical through bore 8 in the drum portion 3 of housing member r1. The housing. con-y struction supports arotar assembly6 (hereinafter usually rotor), via its drive shaft 7.. The rotor is located coaxially of said generally cylindrical through bore 8 of housing member 1. The housing construction further includes a non-rotatably locked pump sleeve 10, containing land defining portions of pump pressure chambers, to be described. The sleeve 10 snugly but readily axially movably occupiesthe housing bore 8.' The sleeve 10 surrounds a generally cylindrical rotor block 12 (fast on the shaft 7 or operatingly integral therewith), and is approximatelycoextensive with the generally cylindrical exterior surface of the rotor block 12.

`The sleeve 10 forms an inner liner for the drum portion 3 of housing member 1 and is in operative effect a rigid means to provide the housing drum portion 3 with a generally elliptical cavity (identified by characters C and'C Fig. 2, describedl later), coaxial with the rotor assembly 6. The inner peripheral surface portions of thecavity, described later, define (in cooperation with the cylindrical exterior surface portions of the -rotor block 12 and circular annular flange portions 14 and 15 thereof operatingly integral therewith and constituted, as shown,

-by annular seal plates mounted on its opposite ends, see

normal to the vertical diametral axis ofthe cavity andv bisects kboth C-shaped chambers between their apical end portions as apparent from inspection of Fig. 2. The chambers C and C', Fig. 3, are substantially closed axially of the pump sleeve 10 or at'its opposite ends by the ilanges or circular seal plates 14 `and 15 which are detachably secured tightly, as by screws 14' and 1S', to respective end surfacesV of the rotor block 12. The seal plates 14 and 15 'are centered on the block 12 by respective axial rib or flange por-tions 12a of the block snugly fitting axial circular bore surfaces 14e of respective seal plates.

` The seal plates or flanges 14 and 15, as supported and spaced apart by main end faces of the rotor block 12, are disposed with their mutually facing planar marginal surface portions in axially overlapping and fairly close clearance relationship to respective smooth end surfaces of the pump sleeve 10. The axialpositions of the yseal plates is fixed by the mountings for lthe vrotor shaft 7,

described later. Radially outward circular peripheral and imperforate surface portions of the flanges or seal plates (on sub-flange portions 14a and 15a respectively) are disposed in fairly close clearance relationship to the bore 8 in the housing drum portion 3. lTheclearances just mentioned result in a relatively `long and tortuous leak path (part radial and part axial) for fluid between surfaces which rotate relative to each other and which are usually exposed to high pressure differential during the pumping operation. The clearance spaces are greatly exaggerated in Fig. 3, being actually assmall as practicable with assurance that the relatively rotating parts will normally be out of contact with eachwother during operation of the pump. p

The rotor block 12, Figs. 2 and 3, has generally radially extending and uniformly angularly spaced vane slots or ways 16 (eight being shown in Fig. 2) intersecting the end surfaces and peripheral surface portions of the block 12; and vane assembly units 18 including-radially movable vane members or vanes 19 (to be more Afully described later herein) slidably occupy the slots or ways 16. The vanes 19 are approximately coextensive axially with the slot-intersected portion of the block 1,2. Suitably rounded sealing surface portions 19 of the vanes 19 (also coextensive with theslots axiallyof the rotor) are maintained in radially outwardly forced sealing contact with the interior peripheral wall surfaces of the pump sleeve 10 partly by centrifugal force augmented by provision of springs 18a operatingly supportedby the bottom walls of slots 16 as Will be further described later.

The vane members 19, as -Will be apparent from Figs. 2 and 3, cooperate with the C-shaped-deningiuteiior surface portions of the sleeve 10 and with sets or pairsof inlet ports 20 and 20 and outlet ports-22 and 22 extending through respective portions of the wall of the sleeve and substantially in common planes transversely of the rotor axis. The ports just above mentioned (cf. LFigs. 2 and 6) are preferably formed by drilling groups-of holes 20h, 22h, etc. through the wall of the sleeve over areas nearly axially coextensive with the sleeve. The various drilled holes, as shown or indicated in the views just above mentioned extend parallel to each other or in directions non-radially of the sleeve 10` andl generally in tangential relationship to inner peripheral wall surfaces of the sleeve thus establishing ow-direction-determining axes for the respective ports 20, 20' etc. which are lparallel to the center lines of the various holes.

A distinct manufacturing advantage in drilling the sleeve-port-forming holes as just above described is that the two groups of holes (e.g. 20h and 20'h Fig-.6.) on each half of the sleeve (one such half` shown in Fig. 6i) can be drilled with the sleeve 10 mounted ina single position in a suitable tool fixture. The functional` advantages of the port directions in sleeve 10 will be brought out later in connection with the operating relationship of the pump sleeve to other portions ofthe pump described below. s

The ports 20, 20 and 22, 22 communicate (a) with respective fl-l and discharge passagesA formed as cavities in the d-rum portion 3 of the housing (as described later) and (b) with the C-shaped cavities C and C' to form or establish a pair of inlet or charging pump chambers F and F disposed diametrically of the rotor block 12 and a pair of outlet or discharge pump chambers P and P' also disposed diametrically of the block 12. The pair of ll or charging chambers F and F and the pair of discharge chambers P and P', which vary in volumeaccording to vane position, are angularly related Ato diametrically located seal regions or yareas S and S between the rotor block 12 and the sleeve 10 (areas bisected by the plane indicated by line 3-3 on Fig. 2 which-line thereby identifies the diametral axis of the sealing surface regions) so that the hydrostatic pressure forces incident to pumping are balanced diametrically of the rotor axis, as Well known in the relevfantarduring the pumping operation.

The diametrically opposite seal areas S and S lie bebetween closely spaced external cylindrical surface portions 12b of rotor block 12 and `adjacent internal surface portions of the pump sleeve 10, and the clearances are on the order of those establishing the leak paths adjacent the seal plates 14 and 15 as described above. The seal areas S and S are of substantial angular or circumferential extent about the rotor axis, being Aapproximately 20, as Shown. That is something over twice the circircumferential width of the vane slots 16. Internal peripheral surface portions T and T of the sleeve 10, located between the pumping chambers F and P and F and P respectively, are concentric with the rotor assembly axis. The surface portions T and T of the sleeve, in cooperation with other above described defining walls of the C-Shaped chambers C and C', including relatively adjacent vane members 19, constitute transport channels of uniform transverse area, as well understood in the vane type pump art. The vane position controlling internal surfaces of the sleeve, all similarly indicated at R, in Fig. 2, and which constitute apical wall portions of the C-shaped chambers `C `and C will be further described later in reference to Fig. 5.

Uniformity of ilow resistance and pressure drop Iis critically important in the inlet or pump-chamber-feeder passages of the pump, especially when volatile liquids (those especially subject to cavitation) are to be handled thereby. Uniformty of flow resistance in the various outlet or discharge passages is, of course, also desirable but is much less important.

Provision of a heavy duty rotary vane type pump arranged for balanced operation as identified above and with main feeder and discharge conduit connections lo- `cated coaxially atsuitable height and atright angles to the rotor axis (as most desirable for field installation and service) can be most electually designed with branch kpassages in the pump body extending from the main inlet and outlet passages around the pump body to cooperating rotor-associated and circumferentially aligned inlet and outlet' ports located diiferent distances from the regions of introduction and discharge of liquid into Iand out of ,left Fig. 2) with `a 4relatively short branch passage leading to near inlet port 20 and a longer passage leading to far inlet port 20 of pump sleeve 10.

Referring more specifically to the main pump housing section or body 1 (especially `as shown in Figs. l, 2, 3 and 4), the formation of liquid supply passages or channels in said body section through and from main inlet channel 30 of `flange formation 25 to the sleeve inlet ports 20 and 20 and from the sleeve outlet ports 22 and 22 to and through main outlet channel 36 of flange formation 26 is such that the ow Iresistance or pressure drop inthe passage portions communicating with the relatively near and far ports isapproximately uniform. That result is attained inter alia, in the arrangement as illustrated, by locating the main inlet and outlet passages or channels 30 and 36 with their preferably common axis in olset relation to the horizontal plane of the rotor axis on the side of that plane (advantageously below or aS shown) on which branch passage . portions 33 and 34 of said channels 30 and 36 respectively are extended around the pump sleeve 10 past the rotor axis and in crosswise relationship to each other (see especially Fig. 1) in order vto communicate at their fluid discharged terminal portions (adjacent the sleeve 10) with associated circumferentially aligned relatively far ports 20' and 22 respectively'through the wall of the pump sleeve 10. Thus the upper branch passages 32 and 35 (Fig. 2) which extend to or from the relatively near `and circumferentially aligned ports 20 and 22 of the sleeve 10 in respect to associated main channels (30 and 36) are not materially shorter than the corresponding lower branch passages v33 and 34 leading to the far ports.

'Additionally,Y for minimizing undesired difference in pressure drop as discussed above, the relatively longer pump chamber feeder and discharge passages leading to their discharge or intake terminal portions'adjacentthe cooperating ports are the less tortuous. This is attained in large part by the already described direction of extent of the effective axes of the inlet and outlet ports in the pump sleeve relative to the pumping chambers and relative to the branch passages leading to and away from the ports of the sleeve in the directions of passage of liquid in and through the pump. As made apparent in Fig. 2 fluid entering the cavity C through the upper branch inlet passage 32 makes a relatively sharp turn in order to get through the sleeve drillings h constituting inlet port 20, whereas the discharge end of the lower inlet branch passage 33 is effectively aligned with the drillings 2071 forming inlet port 20. The outlet branch passages or channels are similarly related to the associated outlet ports of sleeve 1t) as will be apparent.

In addition to the horizontally offset location of main inlet and outlet passages or channels relative to the rotor axis and other features of the'passages described above, and especially in order to encourage easy-filling flow to the inlet portions F and F of the C-shaped chambers C and C the inlet or feed passages, both in the main casting l and in the sleeve 10, are, generally atleast, formed with larger effective transverse areas than those of corresponding portions of the outlet passages. As shown in Figs. 2 and 6, the tangentially extending inletport-forming holes (e.g. 20h) in the pump sleeve 10 are nearly twice as numerous as the-discharge-port-forming holes (e.g. 22h) in the sleeve, all the holes however vpreferably being of uniform diameter for production economy.

In order to encourage the ultimate user of the pump to provide substantial fill capacity conduits in installing the present pump the inlet flange 25 is designed to be coupled to a suitable standard size relatively large diameter feeder conduit (e.g. 3" inner diameter), and the outlet flange 26 is adapted to be coupled to a relatively small diameter but standard discharge conduit (e.g. 2" inner diameter). i

Referring further to the liquid flow passages or channels formed as cavities in body casting 1, liquid entering the inlet passage 30, left Fig. 2, is divided or deflected toward respective branch passage portions 32 and 33 by a suitably shaped rib 30a extending entirely across the main passage 30 and whose surfaces define radially inward wall portions of the branch passages 32 and 33. A similar liquid guide rib 36a extending across the outlet passage or channel 36 assists in merging the outlet branch passages 34 and 3S smoothly therewith. The upper inlet and outlet branch passages 32 and 35 are of generally rectangular elongated form in cross section (not fully illustrated). All the branch passage portions which are formed in the drum portion 3 of the casting 1 are extended laterally, mainly for the sake' of uniformity of Y casting wall thickness, as by transversely aligned horizontally extending cavities (typical disposition indicatedn at 32e and 35e Fig. 2) in available locations not intersected by holes for the end-cap-attaching screws 4' and 5.

As seen by comparison of Figs. l, 2, 3 and 4, the lower inlet branch passage 33, below the deflector 30a, turns downwardly and toward the right vfrom the point of view of a coupler attached to inlet flange 25 and, at the transverse plane of Fig. 3 or directly below the rotor assembly, the passage y33 has the horizontally elongated more or less rectangular form as indicated at 33b in Fig. 3. Lower outlet branch passage 34 turns rightward (same point of view) from the cavity 34a which intersects main casting bore 8 for communication with the pump sleeve discharge port 22, and, below the rotor asy so-that, in the region of section-indicating line 4-4 on passage 33 intersects the through bore 8 in casting 1 in registration with the vertically disposed filler port drillings 20h. The lower outlet branch passage 34 underlies the inlet branch cavity portion 33a,.as shown in Fig. 4, meanwhile turning toward the right in order to merge withl the main outlet passage 36 centrally of the casting 1 in reference to the drum portion 3 and the inlet and outlet flanges 25 and 26. v l

Fig. 4, incidentally, shows substantially the manner in which one of the inlet passage-branch portions (33 only in Fig. 4) is extended laterally at at 33e in appropriate places as already mentioned. The extensions are communicated with Yspaces V and V', Fig. 3, adjacent the end portions of the rotor block 12 through` radial passages such as 33d and 33e, Fig. 4. Thereby the faces of the rotor block 12, Fig. 3, and the attached seal plates 14 and 15 which are exposed axially of the rotor block in said spaces V and V (equal total areas exposed in each) are subjected to balanced and relatively low hydrostatic pressure forces. Further the seal assemblies 44 and 45, Fig. 3, are similarly subjected to relatively low and hydrostatically balanced pressures axially of the assemblies which, particularly, cannot expose the carhon portions 44a and 45a of the seals to destructive forces. n

Outboard bearing assembly 40, left Fig. 3 (fully secured in end cap 5 against axial movement and secured to the rotor shaft against axial movement relatively thereto as will be described) fixes the axial position of the rotor head 12 which preferably is shrink fitted to vthe associated largest diameter portion 7a of the shaft 7. Thus as pump output axially balanced high pressures occur in the planar clearance spaces between the two seal plates 14 and 15 and the associated ends of pump sleeve 10 (portions of the leak paths described above) Vthe pump sleeve is hydrostatically centered between the two seal plates and no axial forces of any consequence are imposed on the bearing assembly which determines the axial position of the rotor.

The four vane-position-control (cam or guide) portions or regions R of the pump sleeve 10, as best shown in Fig. 5, preferably have identical contours. Each region R, as shown, extends for approximately 30" circumferentially of the sleeve 10 about its center or axis O which is also the axis of the rotor. Each vane position control region comprises a planar surface 10b tangent to the adjacent sealing internal surface 10a of the sleeve and which defines, with the yperiphery of the rotor head 12, the seal region S or S of substantial circumferential extent (angle Sx) as earlier described in reference to Fig. 2. The vanes 19 while traversing the planar guide surface 10b are not subjected to centrifugal force but, in the absence of vane loading spring force, would nevertheless stay in sealing contact with surface 10bV because of the inherent tendency for any body to move in a straight line. For operatingly merging the plane surface 10b smoothly into the transport-area-defining concentric internal surface T of the sleeve a suitable arcuate surface 10c is formed on a radius Y whose length is considerably less than the radius of seal surface 10a (radius Y being shown as about half the radius of portion T) the surface 10c being tangent to planar surface 10b and to the arc ywhich defines associated surface T. Thereby the lvanes 19 move from their maximum inward positions (seal regions S or S) to their maximum outward positions (in contact with surface T) in about 30 of rotation (angle Rx) or relatively very quickly in order to minimize intake losses. The charging or intake ports ( holes 20h and 20h), due largely to their tangential direction already described, extend through approximately v(angle Tx plus Rx) on the inside of the sleeve 10', so that the effective fill chambers F and F', after the vanes 4are no longer acting to enlarge the transverse areas of the ll chambers, have ample time Ato become fully charged. The directions of extent of the holes 20h and 20h further favors full charging since the charging flow direction through the intake ports into the chambers C and C is to a large extent tangentially of said chambers. The discharge ports (22 only being shown in Fig. 5) are approximately coextensive circumferentially of the sleeve 1 0 with the associated vane control or camming surfaces R.

The vane assembly units 18, oneV of which is shown in detail in Figs. 7 and 8, in addition to the flat platelike vanes or vane members 19 of rectangular form as shown in Fig. 7 and their springs 18a already mentioned in clude supporting lstrips 18b for the springs occupying the bottoms of respective vane slots 1.6. The springs 18a are preferably helical wirecoils spaced approximately equal distances apart along each vane mainly by respective parallel sockets 50 intersecting the radially inwardly exposed generally flat edge face 51 of the vane, which face lies adjacent the bottom of an associated vane s lot 16 as shown in Fig. 2. The supporting strip 18b has shallow circularsockets 52 for receiving and further positioning associated end coils of respective springs 18a as best shown in Fig. 8.

In order that the spring coils intermediately of the ends of the springs 18a will not be in rubbing contact with the Walls of the sockets 50 in the vanes, the end coils, as 18C and 18d, Fig. 8, of the various springs 18a are of larger diameters than those of the interme- `diate coils. This Vsame coil diameter relationship enables the springs (through tight engagement of their end coils with associated Side wall portions of the sockets 50 of the vanes and the sockets 52 of the positioning strips 18b) to retain together the components comprising each vane assembly 18 for package or unitary insertion into the rotor slots 16 and removal therefrom,

Part or all of the sockets 52 in each spring supporting strip 18b have holes 53 in their bottom Walls intersecting the under face of the strip for uid passage through `the strip as will be explained presently. For lluid communication between the spaces lying radially under the vanes or in the bottoms of the vane slots and whatever ll or discharge chamber (F, F', P or P) the vanes happen to be exposed in, holes 54 in the radially outward portions of the vanes 19 (eccentric to the sockets 50 as shown in fFig. 8) intersect the sockets 50 or some .of them. The sealing rib portions 19 of the vanes 19 trail the associated holes 54 of the vanes in respect to the direction the rotor turns (counterclockwise as indicated in Fig. 2). Thereby, las earlier mentioned, the vanes act as pumping pistons contributing materially to the capacity of the pump, and hydrostatic pressures due to pumping are approximately equalized on the radially outward and radially inward faces or edges of the vanes.

In. order to minimize unbalanced hydrostatic forces diametrically of the rotor assemblyI 6 in event of damage to the Vane seal rib portions 19 (e.g. abrasion or chipping of the ribs as by sand or hard particles in the fluid being pumped)the vane slots 16 are cross connected in pairs diametrally of the rotor head by angularly related passages 56, 57, 58 and 59 (see Fig. 2). These passages can be economically formed in the rotor block 12 and shaft portion 7a after the block is mount- .ed on the shaft. The passages 56, 57, 58 `and 59 are communicated at opposite ends successively with the pressure spaces P and P through the openings 54 in the vanes 19 and the openings 53 in the vane spring positioning strips 1811 already described above.

While the material for the vanes 19 is selected according to use a highly satisfactory vane composition for pumping crude oil for example is inherently strong and tough, acid andhydrocarbon resistant, thermosetting synthetic resin. Such can be moulded and/or machined to the` required shapes or as shown by comparison of Figs. 7. and.8. The springs 18a are preferably made of corrosionI resistant metal for example beryllium copper alloy or stainless steel. The rotor block 12 and sleeve 10 are'preferably tough hard steel. The seal plates 14 and 15 may be bronze but, for greater strength they would also be suitable steel sheathed with a bearing material Suited lfor operation in association with the ferrous metals used for the sleeve 10 and housing 1.

Referring further to Fig. 3 which best illustrates the preferred mounting for the rotor shaft 7, adequate provision is made for inspection of the pump chambers and lfor expeditious removal and replacement of vane units 18, via removal of the end cap 5, i.e. the main housing bore closure which lies outboard with reference vto the pump driving mechanism not shown (coupling, transmission, etc.) which therefore need not be disturbed in order to enable routine inspection and performance of usual service operations.

' Characteristics of end vcap 5 (left, Fig. 3) which are common to both end caps 4 and 5 Will be described below solely in reference to end cap 5; and the reference characters applicable to operationally identical features of the end capswill be mentioned only in respect to end cap 5.

End cap 5 has a stepped diameter generally cylindrical portion 60 for snug slip-fitting relationship to the main casting bore 8, the portion 60 being grooved at 61 for reception of'a resilient or other ring type seal 62 to prevent leakage of low pressure pumped fluid out of space V. An annular closure plate 63, complemented by an easily detachable spring cap 63a adjacent to the outboard end of the drive shaft 7 is disposed in axial alignment with the bearing 'assembly 40. Closure plate 63 is secured in a circular recess or counterbore 64 of the endA cap 5 as by screws 65. An inner face 66 of the plate 63 is forced by the attaching screws 65 against one axial end portion lof the outer race ring member 40a of bearing assembly 40. The inner race ring member 40hV of the bearing assembly is press or shrink fitted to the reduced diameter end portion 7b of shaft 7 against a leftwardly facing shoulder 7c on the shaft. A radially expansible (for release) snap ring 67 occupies a peripheral groove 68 in the outer race ring 40a of the bearing 40, so that the position of the snap ring can determine the position of the bearing assembly 40 (hence the position of the shaft `7 and other parts of the rotor assembly -6` lixedly secured thereto) axially of the housing 1, via the fixed position of the end cap 5 on the main housing. A fairly large clearance space 69 between the annular plate 63 and the bottom of the counterbore or recess 64 in the end cap 5 enables assurance of right- Ward takeup pressure of plate surface 66 against the outer bearing race 40a and, therethrough, rightward pressure of the radially outward margin of the snap ring 67 against the bottom of said counterbore 64. Thereby, when the screws 65 of plate 63 are tightly seated against said closure plate, the shaft 7 is elfectually prevented from' axial movement relative to the pump housing,

Spring cap 63a in alignment with the outboard end of shaft 7 enables ready' access to the shaft (inboard end normally inaccessible) for measuring pump rotor speed after installation and during trial operation of the pump.

The spring loaded seal assembly 44 around the shaft 7 (left Fig. 3), is partially contained in a generally cylindrical sleeve 70 having ring type seals 70a and 70b similar to 62 (previously described), one externally around a portion 44b of the seal assembly 44 and one internally around the cylindrical counterbore surface 72 of end cap 5 into which the sleeve 70 can slide easily. In order for the seal assembly 44 to operate properly the sleeve 70 must be prevented from rotating with the shaft 7; and that function, in the illustrated arrangement, is accomplished by provision of a radial pin 75 carried by the sleeve 70 and of a pin 76 projecting inwardly from the end cap 5 normalto the axis of pin 75 or so as to be in the'path of attempted full circle rotation on part r "mit of the pin 75 with the rotor assembly. -The central openmg, 14e. of the seal plate 14 which ts over the associated rib 12a of the rotor block 12 is larger in diameter than the seal retainer sleeve 70, and alradial slot 141, Fig. 2, intersecting said central opening 14e permits the seal plate 14 to clear the radially extending pin 75 of sleeve 70 during removal of the seal plate `14 out of main casting bore S.

Still referring to Fig. 3, it willbe apparent thatV the end cap can be removed from its illustrated position (leftwardly, Fig. 3), leaving the bearing assembly 40 andthe seal assembly 44 in their illustrated-'positions on their'then cantilever-supported.associated portions of the shaft 7. That end-cap-detachng operation exposes, inter alia, the leftwardly facing surfaces of theseal plate 14 and its attaching screws 14. The seal plate 14 can thus be detached from the rotor assembly and slid out of the casting bore 8, thereby to expose the `outboard ends of the vane assemblies 18.

Extraction of the vane assemblies 18 from their slots or ways 16 of the rotor block is facilitated by provision of threaded sockets 78 (see Fig. 7) inthe end portions of the vanes 19 axially of the rotor assembly 6. The threads and diameters of the sockets 78 can be the same (for example) as those of the screws 14' or 15', which secure the seal plates 14 and 15 to the rotor block (or the same as those which secure the cap 1c, Fig. 2, to the housing 1) whereby readily available screws can be used to extract the vane units or assemblies 18 from the vane slots 16 of the rotor block. Extraction of the vane units 1.8 is accomplished easily when the units are in their maximum outward positions, namely when the units are in the chambersCorC. v f

If the pump sleeve requiresremoval from itsposition for inspection or replacement this can be accomplished through the outboard end of main casting bore 8 after removal of key `1b. Y

During replacement of the end cap 5 (and during its initial installation into the housing 1) the seal ring 7Gb around the sleeve 7 (l of seal assembly 44 is apt to be so expanded radially as to resist entering its receivingcounterbore 72 in the end cap 5. To make certain that the sleeve 70 will be moved yinto seated position without danger of damaging the seal assembly a cuplike metal sleeve 80 is provided around the Vloading springof seal assembly 44 and the iiange portion 81 is so positioned relativer to the sleeve 70 as to thrustl that sleeve approximately intojits properly seated (illustrated) position while the end cap 5 is being initially installed or is being replaced following the above described vane inspection or replacement operations. i

The inboard shaft mounting and seal construction shown at the right in Fig. 3 is basically the same as the outboard construction described above except thatr the outer race ring 41a of bearing assembly 41 has a slip fit in a counterbore 32 in the end cap 4 to permit installation of that end cap over the inboard bearing whose inner race ring 41b is xed to the drive shaft, as by press or shrink iitting. End cap 4 has a radially inwardly extending flange portion 4f shrouding the inboard bearing assembly 41.

The self contained vane assembly or unit 18 constituted by a vane member 19; a spring positioning strip or plate 18b, and the associated coil springs 18a, as earlier above described in reference to Figs. 7 and 8, does not enable the vane units 18 to be very easily inserted into the vane ways or slots 16 except when a guide iixture (such as a double-open-ended sleeve is used to contain the components with the springs 18a in compressed condition, not illustrated). Furthermore if, for self-containment of the components, the -spring end Vcoils (see 18e and 18d in Fig. 8) are tight in the sockets 50 and 52 of the vanes and supporting strips the spring-coils intermediately of the ends of the springs can be subjected to slight torque during cyclical compression and/or expansion. The end coils of the springs may be entirely free from torque restraint by retaining socketwalls in the self-contained vane unit assembly 118 described below in reference to Fig. 9. In Fig. 9 the vane `119 has ('for example, near its two ends axially of the rotor and occupying vrespective regions which, in the Fig. 7 illustrated construction, are occupied by springs 18a) latch devices 120 formed, for example by pins 121 (one shown) suitably fixed to the coil-springsupporting strip 118b; The pin 121, as shown in Fig. 9, projects into a circular bore 122 in the bottom wall of vane 119,.which bore is somewhat larger in diameter than the headportion y124 of the pin 121. Counterbore 125 of bore 122 (shown plugged) forms a shoulder126. When the spring supporting strip 118b andthe vane 119 have their leftward end surfaces disaligned, a small distance, as illustrated at the left in Fig. 9, the head 124 can (with the-springs 18a compressed axially to a greater extent than they ever are in the operation in the pump) be frictionally latched on the Counterbore shoulder 126. Thus it is an easy operation to insert the latched vane units 118 into the rotor block slots 16 in any position of those slots. After insertion the leftward end surfaces of the vanes 119 and the supporting strips are moved into kflush relationship to each other, releasing the latch connec'tions described above; and obviously the-heads 124 of the pins 121 cannot then lbe re-latched on the shoulders 126 during operation of the pump.

In Fig. 3a, the snap ring 67 is of tapered or wedge-like cross sectional form and is seated into a generally cornplementary `groove 68 in the outer bearing race member 40a of bearing assembly 46, so that the snap ring has no side clearance, axially of the rotor assembly 6i, between it and the side-defining surfaces of the groove. In this modication, when the annular plate member 63' is secured in end cap 5 by tightening of attaching lscrews 65, an inner face 66' of the plate 63' clamps the snap ring 67' against the bottom of counterbore 64 of end cap 5, and the snap ring `67' is subjected lsubstantially only to shear stress in holding the rotor assembly 6 axially inl position.

In Fig. 3a it is apparent that the shielding, partially shown at 40C, of bearing assembly 40 provides a labyrinth andi/or corrosive fluids such as can be handled by the A fprese'nt pump. To prevent accumulation of such fluids in '45 thefspaces between the rotor shaft seal assemblies 44 and 45 and the bearingv assemblies 40 andr41 (in case, for example-of ymalfunctioning of the seal assemblies), suitable ydrain passages; lead from the respective spaces just above mentioned to points externally ofthe pump housing. Such passages 40d and 41d Fig.. 3 areindicated as formed in respective end caps'5 and 4, the outer ends of the passaves being adapted for connection to suitabletubing.

The inlet and outlet branch passage or channel vportions 33b and 34h in the main housing member 1, as shown in Fig. 3, have Adrain and iiuid inspection holes 33h and 34h shown closed by suitable threaded plugs.'

Pressure gages or emergency reliefy valve mechanism (neither shown) can be connected at the holes 33h and 34h or at other similar holes (not shown) in appropriate portions ofthe housing.

We claim: n

l. A vane type rotary pump comprising a housing having a cylindrical bore, a rigid metal sleeve lining said bore, a cylindrical rotor for the vanes arranged to operate in a cavity in the sleeve providing with the rotor diametrically-opposite arcuate pumping chambers and diametrically opposite sealing surfaces in a diametrical plane at right angles to that of the pumping chambers, each chamber having inlet ports formed by a. plurality of cylindrical holes in the sleeve having mutually parallel axes which are also parallel to said diametrical plane, a submetrical plane and respective long and short branches extending circumferentially of the sleeve radially outwardly therefrom and communicating the main passages with respectively associated ports, the main inlet passage having a longitudinal axis perpendicular to said diametrical plane and intersecting it in offset relation to the rotor axis in a direction toward 'the long inlet branch;

2. The pump according to claim 1 wherein the sleeve is slidably but non-rotatably tted in the cylindrical bore of the housing, end portions of the rotor having circular anges rigid therewith and overlapping respective ends of the sleeve and -the interior of said bore close to each, thereby establishing in conjunction with the sleeve and housing bore radially and axially extending leak paths, together with bearing means supporting the rotor in axially xed position in the housing and thereby, through the agency of the flanges, determining the axial position of the sleeve.

3. In a rotary pump, a main housing member having an approximately cylindrical bore and closure means for respective ends of the bore, one of said closure means being detachable from the main housing member to expose one end of the bore, means forming a pump barrel concentrically of the bore, a pumping rotor assembly coaxially of lthe bore and having fluid impelling means cooperating with the barrel forming means to pump fluid, said rotor assembly including a supporting shaft, a portion of the shaft having a bearing supporting it in one of said closure means, a ball bearing assembly supporting another portion of 4the shaft in said other closure means, said ball bearing assembly including an inner ball race member fast on the associated portion of the shaft and an outer ball race member slidable in a cylindrical bore portionof said other closure means, the balls of said bearing assembly preventing substantial axial relative movement of the race members axially of the rotor assembly, the outer race member having a retainer ring removably secured thereto marginally 'adjacent a rigid wall surface portion of said other closure means facing axially of the rotor assembly toward said other closure means, a substantially rigid plate member and means detachably clamping that member to said other closure means and meanwhile operating to force the retainer ring tightly against saidrigid wall surface portion of that closure means, said means forming the pump barrel including a generally cylindrical sleeve keyed to the main housing member and axially movable in and externally mating 'the cylindrical bore and further including seal plates rigid with opposite effective end portions of the rotor assembly marginally overlapping respective end surface portions of the sleeve so that the position of the sleeve axially of the bore is maintained by said ball bearing'assembly and its associated elements.

4. In a vane type rotary pump having a generally cylindrical radially slotted rotor for the vanes operating in a cavity providing an arcuate pumping chamber and sealing surface regions at circumferential ends of the chamber and inlet and discharge passages for fluid communicating with the chamber, a self contained vane assembly in a slot of Ythe rotor and comprising a vane element slidably fittingV the slot, an auxiliary member slidably fltting the slot, the vane element and auxiliary member being of approximately equal length and coextensive with the slot axially of the rotor, and radially acting compression spring means between said vane element and auxiliaryv member, a plate detachably secured to one end of the rotor and defining one axial end of the slot, and retaining latch means comprising a` pair of headed parallel pins on theauxiliary member loosely occupying respective sockets in the vane element, the sockets having shoulders positioned to abut the respective heads of the pins when the-auxiliary memberV and vanev element are in an abnormal relatively offset position axially of the rotor for holding the springs in compressed conditions, the headsI releasing the shoulders when the element and member have been moved in that direction to a normal working mutually registering position.

References Cited in the flle of this patent UNITED STATES PATENTS 1,101,688 Diamant .Tune 30, 1914 1,635,006 Oliver July 5, 1927 1,769,647 Press July 1, 1930 1,776,452 Rosenthal Sept. 23, 1930 1,807,392 Davis May 26, 1931 1,898,914 Vickers Feb. 21, 1933 2,170,786 McElroy Aug. 22, 1939 2,255,785 Kendrick Sept. 16, 1941 2,400,286 Buckbee May 14, 1946 2,491,100 Frei ,Dec. 13, 1949 2,498,029 Clerc Feb. 21, 1950 2,498,826 Ruona Feb. 28, 1950 2,525,619 Roth et al. Oct. 10, 1950 2,545,238 MacMillin et al.v Mar. 13, 1951 2,558,837 Frei July 3, 1951 2,650,573 Hickman Sept. 1, 1953 2,696,787 Jaworowski et al. Dec. 14, 1954 2,731,919 Prendergast Jan. 24, 1956 2,762,312 Adams'et al. Sept. 11, 1956 2,787,959 Jeannin et'al Apr. 9, 1957 2,856,860 Roth Oct. 21, 1958 FOREIGN PATENTS 21,191 Norway Feb. 20, 1911 409,958 France Mar. 4, 1910 `508,748 i Germany Oct. 1, 1930 V` 583,973

France Nov. 12, 1924

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